Spark Advance Tests

Power & vacuum transducer tests:

1. Ensure engine is fully warmed up and the temperature sensor is connected and operating properly.
2. Set ignition timing to specifications.
3. Place a piece of paper between curb idle adjusting screw and carburetor switch, see figure, or ensure curb idle adjusting screw is not contacting carburetor switch.
4. Remove and plug vacuum transducer line.
5. Using a suitable hand operated vacuum pump, apply 16 inches of vacuum to Spark Control Computer transducer.
6. Increase engine speed to specifications, wait 1 minute. Advance specifications are in addition to basic timing advance. On systems equipped with an accumulator, the specified time must be reached with the carburetor switch ungrounded before checking the specified spark advance schedule (see Specifications, Electrical). Electronic Spark Control Specifications
7. If the computer fails to obtain specified settings, replace computer.